scholarly journals Fourier-Domain Optical Coherence Tomographic Assessment of Changes in the Schlemm’s Canal of Nonglaucomatous Subjects After Keratoplasty

2021 ◽  
Vol 12 ◽  
Author(s):  
Yujin Zhao ◽  
Yue Li ◽  
Jiaxu Hong ◽  
Qihua Le ◽  
Jianjiang Xu
Keyword(s):  
Early Period ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Fourier Domain ◽  
Optical Coherence ◽  
Schlemm’S Canal ◽  
Schlemm's Canal ◽  
Anterior Lamellar Keratoplasty ◽  
The Impact

Purpose: This study aimed to evaluate the impact of keratoplasty on the in vivo anatomical structures in the Schlemm’s canal (SC) of nonglaucomatous subjects using Fourier-domain optical coherence tomography (FD-OCT).Methods: Sixty-six nonglaucomatous eyes that underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), or triple surgery were enrolled in this prospective, comparative, observational study. The SC imaging was performed using FD-OCT before and after surgery in both the nasal and temporal quadrants. Patient demographics, SC parameters [e.g., cross-sectional area (CSA), meridional diameter of SC (MSC), sagittal diameter of SC (SSC), and circumference (CCF)], and the correlations between the variation of SC parameters and intraocular pressure (IOP) were analyzed.Results: The mean age of all subjects was 40.27 ± 18.97 years. Among all cases, the nasal, temporal, and mean MSC significantly decreased on the first day after surgery and then increased at 1 week (p = 0.04, 0.017, and 0.01, respectively). Temporal CSA (tCSA), temporal MSC (tMSC), and temporal circumference (tCCF) after PK (p = 0.017, 0.020, and 0.018, respectively) and nasal MSC (nMSC) after DALK (p = 0.025) decreased significantly on the first day after surgery. The shift in mean IOP was significantly correlated with the changes in tMSC (r = 0.341, p = 0.003) and CCF (r = 0.207, p = 0.048).Conclusion: SC had significant in vivo morphological changes in the early period after keratoplasty in nonglaucomatous eyes, accompanied with elevation of IOP. Early intervention might be necessary to prevent secondary glaucoma early after keratoplasty.

scholarly journals Anterior Segment Optical Coherence Tomography Signs of Local Dilatation Effect of a Micro-Stent on Schlemm’s Canal

2018 ◽  
Vol 10 (2) ◽  
pp. 184-187
Author(s):  
Kevin Gillmann ◽  
Giorgio Enrico Bravetti ◽  
Kaweh Mansouri ◽  
André Mermoud
Keyword(s):  
Optical Coherence Tomography ◽  
Trabecular Meshwork ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Schlemm’S Canal ◽  
New Device ◽  
Schlemm's Canal ◽  
Canal Diameter ◽  
Trabecular Bypass

Introduction: The iStent inject® (Glaukos Corporation, CA, USA) is a relatively new device designed to be implanted ab-interno through the trabecular meshwork. This is, to the best of our knowledge, the first in-vivo description of a trabecular bypass device visualised with anterior segment optical coherence tomography (AS-OCT), and report of its structural effect on Schlemm’s canal. Case Report: A 74 year-old female patient suffering from long-standing primary open-angle glaucoma and nuclear sclerosis underwent cataract surgery combined with the implantation of two iStent injects®. Surgery was uncomplicated and achieved intraocular pressure (-1 mmHg) and medication (-2 molecules) reduction at 6 months. Under AS-OCT (Spectralis OCT, Heidelberg Engineering AG, Germany) the stent appears as a 300 μm long hyper reflective hollow device within the trabecular meshwork. Approximately a third of it protruded into the anterior chamber. Profound OCT signal loss was notable within the shadow of the device. A second AS-OCT section 500 μm beside the microstent shows a markedly dilated Schlemm’s canal, with a major diameter of 390 μm. Discussions: This report confirms that AS-OCT is a suitable technique to assess microstent positioning, and provides a first report on the in-vivo appearance of a functioning stent. It also indicates that iStent injects® could have a tangible effect on adjacent portions of Schlemm’s canal with, in this case, a 220% increase in canal diameter compared to the observed average (122 μm). This suggests the IOP-lowering effect of trabecular bypass devices could rely on a  dual mechanism involving Schlemm’s canal dilatation.

scholarly journals Demonstration of Optical Coherence Tomography Guided Big Bubble Technique for Deep Anterior Lamellar Keratoplasty (DALK)

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 428
Author(s):  
Shoujing Guo ◽  
Nicolas R. Sarfaraz ◽  
William G. Gensheimer ◽  
Axel Krieger ◽  
Jin U. Kang
Keyword(s):  
Optical Coherence Tomography ◽  
Rejection Rate ◽  
Cell Loss ◽  
Needle Insertion ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Insertion Depth ◽  
Anterior Lamellar Keratoplasty ◽  
Big Bubble

Deep anterior lamellar keratoplasty (DALK) is a highly challenging procedure for cornea transplant that involves removing the corneal layers above Descemet’s membrane (DM). This is achieved by a “big bubble” technique where a needle is inserted into the stroma of the cornea down to DM and the injection of either air or liquid. DALK has important advantages over penetrating keratoplasty (PK) including lower rejection rate, less endothelial cell loss, and increased graft survival. In this paper, we successfully designed and evaluated the optical coherence tomography (OCT) distal sensor integrated needle for a precise big bubble technique. We successfully used this sensor for micro-control of a robotic DALK device termed AUTO-DALK for autonomous big bubble needle insertion. The OCT distal sensor was integrated inside a 25-gauge needle, which was used for pneumo-dissection. The AUTO-DALK device is built on a manual trephine platform which includes a vacuum ring to fix the device on the eye and add a needle driver at an angle of 60 degrees from vertical. During the test on five porcine eyes with a target depth of 90%, the measured insertion depth as a percentage of cornea thickness for the AUTO-DALK device was 90.05 % ± 2.33 % without any perforation compared to 79.16 % ± 5.68 % for unassisted free-hand insertion and 86.20 % ± 5.31 % for assisted free-hand insertion. The result showed a higher precision and consistency of the needle placement with AUTO-DALK, which could lead to better visual outcomes and fewer complications.

scholarly journals Descemetic and Predescemetic DALK in Keratoconus Patients: A Clinical and Confocal Perspective Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Domenico Schiano-Lomoriello ◽  
Rossella Annamaria Colabelli-Gisoldi ◽  
Mario Nubile ◽  
Francesco Oddone ◽  
Giorgio Ducoli ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Layer By Layer ◽  
In Vivo Confocal Microscopy ◽  
Descemet Membrane ◽  
Anterior Lamellar Keratoplasty ◽  
A Minor ◽  
Big Bubble

Purpose. To evaluate the clinical outcomes and in vivo confocal microscopy (IVCM) features of keratoconus patients who underwent deep anterior lamellar keratoplasty (DALK).Methods. DALK was performed using the big bubble technique in all the patients. If the bubble was not successful to bare the descemet membrane, a manual dissection layer-by layer was performed to expose a deep stromal plane close to the DM. The patients were divided in two groups depending on the intraoperative baring of the descemet membrane: predescemetic DALK (PD-DALK) and descemetic DALK (D-DALK) group.Results. One month after surgery the D-DALK patients show an increase of mean BCVA. In the PD-DALK group mean BCVA did not show significant improvement as compared to preoperative values. At 6 months after surgery mean BCVA was found to be similar in both groups. At 1 month IVCM the peak of reflectivity of the interface was lower in D-DALK group compared to PD-DALK. At 6 months the values of reflectivity were comparable.Conclusions. At 1 month D-DALK seems to lead to a minor interface reflectivity and to a better BCVA; these differences disappear after 6 months and the values of interface reflectivity and BCVA are comparable between D-DALK and PD-DALK.

Longitudinal changes in corneal leucocyte density in vivo following transplantation

2018 ◽  
Vol 103 (8) ◽  
pp. 1035-1041 ◽  
Author(s):  
Scott Hau ◽  
Bronagh Clarke ◽  
Caroline Thaung ◽  
Daniel F P Larkin
Keyword(s):  
Graft Rejection ◽  
Density Measurement ◽  
Topical Steroid ◽  
Steroid Treatment ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
In Vivo Confocal Microscopy ◽  
Post Transplant ◽  
Anterior Lamellar Keratoplasty

AimsTo prospectively evaluate the changes in corneal leucocyte density with in vivo confocal microscopy (IVCM) following transplantation and to determine if leucocyte density post-transplant is an indicator of graft rejection risk.MethodsIVCM imaging of cornea pre-transplant and post-transplant at 1 week, 1, 3 and 12 months. The changes in leucocyte density associated with diagnosis, vascularisation, type of keratoplasty, topical steroid and immunosuppression treatment, allograft rejection and failure within 4 years post-transplant were analysed.ResultsSub-basal nerve plexus total central leucocyte density (SBNP-TCLD) varied with diagnosis (p<0.001), interval post-transplant (p<0.001), degree of vascularisation (p=0.001) and rejection episodes in eyes off topical steroid (p=0.01). The highest SBNP-TCLD was found in eyes with inflammation pre-transplant. Mean 12-month SBNP-TCLD in eyes which had rejection episodes was almost double that in eyes which did not (79.0 and 39.8 cells/mm2, respectively). SBNP-TCLD >63.5 cells/mm2 was associated with a higher risk of rejection within 1 year (p=0.04) and 4 years (p=0.007). Changes in leucocyte density on the donor endothelium significantly differed between penetrating keratoplasty and deep anterior lamellar keratoplasty grafts (p<0.01) and in those in which rejection episodes were observed (p<0.001).ConclusionsLeucocyte density varies with corneal diagnosis, extent of vascularisation and interval post-transplant. Topical steroid treatment is associated with reduced leucocyte density and risk of graft rejection. Higher endothelium leucocyte density correlates significantly with previous or subsequent rejection episodes. Leucocyte density measurement by IVCM may be useful in identifying transplants at risk of rejection.

In vivo biometric evaluation of Schlemm's canal with spectral-domain optical coherence tomography in pseuduexfoliation glaucoma

2016 ◽  
Vol 94 (8) ◽  
pp. e688-e692 ◽  
Author(s):  
Serhat Imamoglu ◽  
Mehmet S. Sevim ◽  
Oksan Alpogan ◽  
Nimet Y. Ercalik ◽  
Esra Turkseven Kumral ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Schlemm’S Canal ◽  
Schlemm's Canal
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